Evolutionary perspective emphasizes two crucial variables affecting partner choice: sex of the chooser and the short-term vs. long-term context of mating. Based on Darwin's sexual selection theory and Trivers's theory of parental investment, numerous hypotheses have been proposed about different sexual strategies of women and men, and different strategies that both sexes apply when choosing a partner for a long-term or a short-term relationship. This lecture will present our studies in which we addressed some of those hypotheses. Firstly, are there sex differences in preferences for certain characteristics of the partner and do they differ in a short-term and long-term mating context? Secondly, how does the self-perceived mate value influence the preferences in mate choice? Thirdly, although the sex differences in pursuing short-term relationships are well documented, the individual differences within each sex have been neglected. Therefore we tried to establish whether there were differences in the tendency to pursue short-term relationships between groups of different age, income and educational level. Fourthly, as previous results indicate the correlation of women's reproductive behaviours with the levels of sex hormones, in a series of studies we tried to establish the variations in some of those behaviours in various phases of the menstrual cycle. Taken together, these results enable us to make some inferences and to propose new hypotheses about sex differences in mating strategies in short-term and long-term context, interindividual differences in those strategies within each sex, and the effect of hormonal variations during the menstrual cycle on women's mating behaviour.